Seeing the light in bone metabolism imaging

Conventional in vivo imaging of bone metabolism is dominated by gamma-ray bone scintigraphy: a technique in which gamma-ray emissions from radioactively labeled regions of metabolically active bone are mapped. More recently, however, near-infrared fluorescent probes have been developed that optically emulate these radionuclides. Although still in their infancy, techniques based on the use of such functionally targeted fluorophores might one-day offer improved resolution, sensitivity and speed in bone metabolism imaging -- without any of the health risks posed by the internalization of radioactive sources.